One of the most musically convincing systems I've heard in a store was a pair of Virgos driven by a VAC Avatar tube integrated. It generated 60/60 watts in pentode operation, and something like 28/28 in pseudo-triode mode. Great option. The room was sizable and in pentode mode, power was sufficient whenever triode mode ran out of oomph. The system blew away everything bigger and more expensive in the store at that time.
Phil
Phil